Polycarbonates, poly(ester-carbonates), and polyarylates are well known thermoplastic materials which, due to their many advantageous physical properties, find use as thermoplastic engineering materials in many commercial and industrial applications. These resins, for example, exhibit excellent properties of toughness, flexibility, impact strength, optical clarity, and heat resistance. All such resins may generally be prepared by the reaction of a dihydric phenol, such as bisphenol-A, with a carbonate precursor and/or an aromatic dicarboxylic acid.
These resins, particularly polycarbonate, have been commonly blended with other resins to produce blends having various modified properties. For example, blends of these resins with a second and even third thermoplastic resin can lead to blends which not only have the above mentioned properties but additionally have excellent properties for which polycarbonate, poly(ester-carbonate), and polyarylate may not otherwise be recognized, such as ductility, solvent resistance, and resistance to brittle failure.
For some important applications, i.e. automotive parts, it is important that such resins have enhanced chemical resistance to aggressive solvents, for example, acetone, aromatic solvents, gasoline, and the like, to a degree which may not be necessary in most other applications. Herein, it is proposed to achieve the necessary levels of solvent resistance in combination with excellent levels of other necessary properties, including transparency, by use of certain novel blends of polycarbonate, poly(ester-carbonate), and polyarylate with polyamide.
Therefore, it is an object of the present invention to produce blends containing polycarbonate, poly(ester-carbonate), and polyarylate which otherwise exhibit the desirable properties of such resins including transparency, but which also exhibit excellent solvent resistance, ductility, and resistance to brittle failure. It is also an object of the present invention to produce molded articles from blends containing the same.